answer: Histograms
I might be wrong, but I believe that a stem and leaf plot makes it easy to find the mean as the quantities are expressed... Dot plot and frequency table pretty much do the same thing by expressing the number of times a number appears.
All of these data sets represent SINGULAR numbers as of data.
Histograms, though, show data in intervals so it is not possible as meamean needs explicit data to find the average and not a grouping...